German police arrest suspect in Borussia Dortmund bus attack

German police have arrested a man on suspicion of carrying out the bomb attack on the Borussia Dortmund team bus last Tuesday.

Defender Marc Bartra, a Spain international, and a police officer were injured in the triple blasts as the players and coaching staff left a hotel ahead of a Champions League match in Germany.

Prosecutors said the suspect, identified only as 28-year-old Sergej W, a dual German and Russian national, was detained on Friday.

He is accused of attempted murder, inflicting serious bodily harm and causing an explosion, police said in a statement.

He is believed to have carried out the attack for financial reasons and had speculated on Dortmund's share value dropping after the bombing.

Prosecutors revealed he had bought a large number of so-called put options for shares of the football club.

These would have entitled him to sell the 15,000 shares at a pre-determined price, resulting in a substantial profit if their value had fallen in the meantime.

"A significant share price drop could have been expected if a player had been seriously injured or even killed as a result of the attack," said prosecutors.

Three identical letters were found at the scene, linking the attack to German involvement in the fight against Islamic State in Syria. But there were doubts over their authenticity.